I made some vanilla vodka back when. The best recipe I have come up with is:
1. Go to http://www.culinarydistrict.com/Product ... as-4-Count
and pick up a couple of those Tahitian beans. Look at them, feel them, smell them, slit one from end to end and strip the vanilla out of the middle. It's a dark brown paste, a little thinner than canned tomato paste. Thicker than spaghetti sauce, though. They're kind of expensive, but you can use them as the standard by which to judge the quality of your vanilla beans you buy from elsewhere. The Madagascar bourbon vanilla beans are dry and crusty by comparison. The ones at Safeway are just horrible, I wouldn't bother. You won't either, once you know the standard by which to judge.
2. Get out your vacuum sealer and Ball jar attachment. Pour your distillate into a ball jar, slice your beans from end to end to facilitate the transfer of material from the inside of the bean to your distillate, cap, and suck 28 pounds of vacuum on the bottle. Watch the bubbles form on the surface of the bean, and watch the vanilla disperse from inside the bean and infuse the distillate. Allow the pressure to stay on that infusion for a week or two. Once the liquid is an opaque and dark brown, you can unseal the cap and enjoy.
3. I toss the beans at that point. I want the most fragrant and tasty part of the bean infused into my distillate, not the taste of the fibrous husk.
I have not made vanilla vodka for a couple years, but it's definitely in my plans for the near future. It was absolutely delicious.
Another one that was very good was to take a bag of Trader Joe's flash frozen peach slices and a bag of Trader Joe's flash frozen black cherries, and pack a couple Ball jars with fruit. Add distillate, give an inch of headspace. For this recipe I would use the strongest distillate I had available, because the fruit juice will dilute your distillate quite a bit. Pump 28 pounds of vacuum, let 'er sit a week, strain, and store.
Other infusions I had a lot of luck with were black pepper, sliced ginseng root, sliced ginger root, juniper berries (a little goes a long way), cinnamon sticks (a little goes a long way), orange zest, lemon zest, coriander, anything else that goes in/with gin, pears, peaches, apples, etc. I stay away from strawberries because the woody taste of the seeds makes its way into the distillate and dominates. I haven't done marion berries... wonder how they'd work out. Blueberries tend to carry the woody taste of the woody parts of the berries.
I found a lot of success with using separate Ball jars for each kind of fruit or spice, and combining them into whatever kind of thing I cared to make later. You never know what's going to tickle your palate.